I created a login system on 000webhost using php. But when running it, Notice: session_start(): Ignoring session_start() because a session is already active in /storage/ssd3/664/19432664/public_html/admin/login.php on line 60
Warning: Cannot modify header information - headers already sent by (output started at /storage/ssd3/664/19432664/public_html/admin/login.php:60) in /storage/ssd3/664/19432664/public_html/admin/login. php online 68 The said error occurs. Also, when it is refreshed once again, it redirects to welcome.php and works correctly. Below are the codes of those pages. Please help me.
login.php:-
<?php
// Initialize the session
session_start();
// Check if the user is already logged in, if yes then redirect him to welcome page
if(isset($_SESSION["loggedin"]) && $_SESSION["loggedin"] === true){
header("location: welcome.php");
exit;
}
?>
<?php
// Include config file
require_once "config.php";
// Define variables and initialize with empty values
$username = $password = "";
$username_err = $password_err = $login_err = "";
// Processing form data when form is submitted
if($_SERVER["REQUEST_METHOD"] == "POST"){
// Check if username is empty
if(empty(trim($_POST["username"]))){
$username_err = "Please enter username.";
} else{
$username = trim($_POST["username"]);
}
// Check if password is empty
if(empty(trim($_POST["password"]))){
$password_err = "Please enter your password.";
} else{
$password = trim($_POST["password"]);
}
// Validate credentials
if(empty($username_err) && empty($password_err)){
// Prepare a select statement
$sql = "SELECT id, username, password FROM users WHERE username = ?";
if($stmt = mysqli_prepare($link, $sql)){
// Bind variables to the prepared statement as parameters
mysqli_stmt_bind_param($stmt, "s", $param_username);
// Set parameters
$param_username = $username;
// Attempt to execute the prepared statement
if(mysqli_stmt_execute($stmt)){
// Store result
mysqli_stmt_store_result($stmt);
// Check if username exists, if yes then verify password
if(mysqli_stmt_num_rows($stmt) == 1){
// Bind result variables
mysqli_stmt_bind_result($stmt, $id, $username, $hashed_password);
if(mysqli_stmt_fetch($stmt)){
if(password_verify($password, $hashed_password)){
// Password is correct, so start a new session
session_start();
// Store data in session variables
$_SESSION["loggedin"] = true;
$_SESSION["id"] = $id;
$_SESSION["username"] = $username;
// Redirect user to welcome page
header("location:welcome.php");
} else{
// Password is not valid, display a generic error message
$login_err = "Invalid username or password.";
}
}
} else{
// Username doesn't exist, display a generic error message
$login_err = "Invalid username or password.";
}
} else{
echo "Oops! Something went wrong. Please try again later.";
}
// Close statement
mysqli_stmt_close($stmt);
}
}
// Close connection
mysqli_close($link);
}?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Login</title>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
<style>
body{ font: 14px sans-serif; }
.wrapper{ width: 360px; padding: 20px; }
</style>
</head>
<body>
<div class="wrapper">
<h2>Login</h2>
<p>Please fill in your credentials to login.</p>
<?php
if(!empty($login_err)){
echo '<div class="alert alert-danger">' . $login_err . '</div>';
}
?>
<form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
<div class="form-group">
<label>Username</label>
<input type="text" name="username" class="form-control <?php echo (!empty($username_err)) ? 'is-invalid' : ''; ?>" value="<?php echo $username; ?>">
<span class="invalid-feedback"><?php echo $username_err; ?></span>
</div>
<div class="form-group">
<label>Password</label>
<input type="password" name="password" class="form-control <?php echo (!empty($password_err)) ? 'is-invalid' : ''; ?>">
<span class="invalid-feedback"><?php echo $password_err; ?></span>
</div>
<div class="form-group">
<input type="submit" class="btn btn-primary" value="Login">
</div>
<p>Don't have an account? <a href="register.php">Sign up now</a>.</p>
</form>
</div>
</body>
</html>
welcome.php:-
<?php
// Initialize the session
session_start();
// Check if the user is logged in, if not then redirect him to login page
if(!isset($_SESSION["loggedin"]) || $_SESSION["loggedin"] !== true){
header("location: login.php");
exit;
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Welcome</title>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
<style>
body{ font: 14px sans-serif; text-align: center; }
</style>
</head>
<body>
<h1 class="my-5">Hi, <b><?php echo htmlspecialchars($_SESSION["username"]); ?></b>. Welcome to our site.</h1>
<p>
<a href="reset-password.php" class="btn btn-warning">Reset Your Password</a>
<a href="logout.php" class="btn btn-danger ml-3">Sign Out of Your Account</a>
</p>
</body>
</html>
source https://stackoverflow.com/questions/73858463/cannot-modify-header-information-in-login-system
Hello, my name is Muhammad Athar. I'm a 17 year old student. I'm a Web Developer, Designer and Freelancer.
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